Primer blowby - 9 mm handloads - update
Recap....
Three boxes of factory cartridges (Blazer, Magtech, Fiocchi – 150 total) were fired and then reloaded 9 times with no indication of primer blow-by or leakage. However, while there was no primer leakage, incipient case fatigue was observed on all Magtech and Fiocchi cases as shown in the accompanying photos. The ridge seen in the photos is barely discernible when running a fingernail across it and only appears over one half of the case (approximately), at the half where the extractor engages the case. There was no indication of case fatigue in any of the Blazer cases.
The Magtech and Fiocchi cases will be scrapped and recycled but I will continue to reload the Blazer cases until such time as an anomaly appears. Two case cleaning methods were used, stainless steel pins (Magtech and Fiocchi cases) and barley grain (Blazer). There was absolutely no visible difference with regard to primer pocket condition between the two methods over the number of reloads.
With regard to the primer leakage condition discussed in this thread and after some reflection on the problem I believe the leakage may have been related to the primers given that this is the only common element other than the cleaning method which has been shown above not to be an issue.
I believe I had indicated previously that CCI 500 SPPs were used exclusively but I recall that I also had one box (1000) of Remington 1-1/2 SPPs and possibly some of those primers may have been slightly undersized. Unfortunately I cannot reconcile the start of the primer leakage with the use of the Remington primers. For the 9 reloads mentioned above, totaling 1350 rounds, only CCI 500 SPPs were used.
For some reason the website would not allow the photos to be uploaded. I will do so when the issue is resolved.